Shuttle mechanisms with cam lock



United States Patent '9 V,

SHUTTLE MECHANISMS WITH CAM LOCK Charles A. Kessler, Plainfield, N.J., assignor to The Singer Manufacturing Company, Elizabeth, N.J., a corporation of New Jersey Filed Oct. 8, 1957, Ser. No. 688,883

2 Claims. (Cl. 112-196) The present invention relates to sewing machines and particularly to a shuttle mechanism of a sewing machine.

The shuttle housing of a shuttle type sewing machine usually includesan open-sided internal circular raceway, the open side of which is closed by a shuttle cap that is resiliently held in place by a leaf spring abutting at its ends against the shuttle housing and the shuttle cap and having a screw extending through an aperture in the spring and threaded into the housing. When thread becomes jammed between the bearing rib of the shuttle and the raceway in the shuttle housing, it is often necessary to release the shuttle to free the thread.

With a shuttle that rotates clockwise at loop seizure with the beak of the shuttle arranged to the inside of the needle, which is the construction employed in most shuttle machines, the resiliently mounted shuttle cap is located on the inside of the needle so that when the shuttle is forced laterally against the resilient mounting of the cap thread, it will move away from the path of the needle. Since the screw associated with the shuttle cap retaining spring is therefore located on the inside of the shuttle and because it is very diflicult to back off the screw in order to release the shuttle, the usual practice is to remove the whole shuttle mechanism. To obviate this task, some machines have been provided with a socalled snap-out cap in which the cap is mounted on the outside of the shuttle housing and is held by pivoted latches. However, in such a construction, when thread becomes jammed and the shuttle is dislodged, it will move against the resilient action of the cap outward.y into the path of the needle, thus breaking the needle. For this reason, the use of such snap-out shuttle caps represents at best a compromise.

At the same time, there are many shuttle machines in which a snap-out shuttle cap cannot be used because, for example, of the characteristics of a particular feeding mechanism that is required Where the elements of the feeding mechanism would interfere with the outward movement of the shuttle cap and with the use of latches on the outside of the shuttle mechanism.

In accordance with the above it is an object of this invention to provide a simple, practical and economical means for effecting release of the shuttle of a sewing machine to provide for freeing jammed thread. The shuttle mechanism in accordance with this invention is particularly useful with a shuttle cap mounted upon the inside of the shuttle mechanism.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawing in which:

Fig. 1 is a fragmentary sectional view of a sewing machine having a shuttle cap retaining means constructed in accordance with the present invention.

1, 2,966,870 Patented Jan. 3, 19 61 Fig. 2 is a fragmentary sectional view taken substantially on the line 22 of Fig. 1.

Fig. 3 is a fragmentary view of a portion of Fig. l and illustrating the parts in a position in which the leaf spring is relaxed.

Fig. 4 is a detail view, in plan, of the cam means per se for adjusting the shuttle cap retaining spring, as illustrated in Fig. 1.

In the drawings there is illustrated a bed plate 1 of a sewing machine having an integral depending foot 2 and a pair of spaced opposed lugs 3. At the point of stitch formation, the bed plate 1 has a throat plate 4. The illustrated mechanism includes a well-known type of feeding mechanism including an intermittently operated rotary feed wheel 5 extending through a slot in the throat plate 4 and against which the work is held by a presser roller 6.

A reciprocating needle 7 is operated through an aperture in the throat plate and cooperates beneath the bed plate 1 with a shuttle mechanism in the formation of lock stitches. The shuttle mechanism comprises a housing 8 that is secured to the lugs 3 by screws 9, Fig. 2, which extend through the shuttle housing 8 and are threaded into the lugs 3. The housing 8 has an internal circular raceway 10 in which is journaled a bearing rib 11 of a shuttle 12. Oscillation is imparted to the shuttle in timed relation to the reciprocation of the needle 7 by a shuttle driver 13 mounted upon the end of a shaft 14 journaled longitudinally of the bed.

As herein used, the inside of the shuttle mechanism is at the right in Fig. l, which is the side adjacent to the standard of the machine (not shown) while the outside of the shuttle mechanism is at the left in Fig. 1, which is the side adjacent to the free end of the bed plate 1.

The raceway 10 is formed at the inside of the shuttle housing 8 and is open at the inside in that it includes only a bottom wall 15 and outside wall 16 formed in the shuttle housing. The open inside of the raceway is closed by a separable cap 17 in the form of a discontinuous ring. The cap 17 is located by two pins 18 extending from the housing .8 through apertures in the cap 17, and it is resiliently held in place by a substantially U-shaped leaf spring 19 having a pair of diverging legs 20 and a heel 21. The legs 20 are arranged to engage the cap 17 at substantially diametrically opposite points and thereby resiliently urge the cap 17 against the housing 8. The pins 18 which extend beyond the cap 17 are also used to position the ends of the legs 20 on the cap. The bottom of the heel 21 is turned at substantially a right angle to provide a flange 22, the free end of which abuts against the housing 8 and spaces the heel of the spring from the housing. The heel 21 is provided with an aperture 23 through which extends the shank of a pivot stud 24 threaded into the shuttle housing 8 and having a head 25. A cam plate 26 is loosely mounted on the stud 24 for turning and is disposed between the head 25 and the spring 19. The cam plate 26 has a pair of diametrically opposed cam lobes 27 on the face thereof adjacent to the spring 19 and is provided with a handle 28 to provide for manually turning the same.

The cam plate 26 and the lobes 27 thereon are dimensioned so that in the position illustrated in Figs. 1 and 2, the lobes engage against the heel 21 of the spring 19 at a point between the flange 22 and the ends of the legs 20 which engage the cap 17. Thus, in the operative position of the handle 28, the spring 19 is flexed resiliently to bias the cap 17 against the housing 8. The lobes 27 on the cam-plate 26 located so that when the handle is turned at a right angle from the operative position illustrated in Figs. 1 and 2 to the inoperative position illustrated in Fig. 3, the cam lobes 27 will lie above and below the heel 21 of the spring 19, as illustrated in Fig.

3, thus relaxing the spring 19 to free the shuttle 12 in the raceway and thereby permit clearing or withdrawing thread which has jammed the shuttle in its raceway.

. Numerous alterations of the structure hereindisclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of my invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.

Having thus described the nature of the invention, what I claim herein is:

1. In a sewing machine, a shuttle mechanism comprising a stationary shuttle housing having an. open-sided internal circular raceway, a shuttle having a bearing rib journaled in said raceway, a separable shuttle cap for closing the open side of said raceway, and means for resiliently urging said shuttle cap against said housing comprising a leaf spring having the one face thereof in engagement with said shuttle at one end and said shuttle cap at the other end, a stud mounted on said housing adjacent to said spring, a cam plate mounted for turning on said stud and having a portion thereof overlying an intermediate portion of said spring, a cam lobe on the face of said portion of said cam plate adjacent to said spring for moving into and out of engagement with the intermediate portion of said spring as said cam plate is turned for flexing and relaxing said spring as said cam plate is turned and thereby varying the action of said spring on said shuttle cap, and means for manually turning said cam plate.

2. In a sewing machine, a shuttle mechanism comprising a stationary shuttle housing having an open-sided internal circular raceway, a shuttle having a bearing rib journaled in said raceway, a separable shuttle cap for closing the open side of said raceway, and means for resiliently urging said shuttle cap against said housing comprising a leaf spring having the one face thereof in engagement with said shuttle housing at one end and said shuttle cap at the other end, a stud mounted on said housing and extending through an aperture in an intermediate portion of said spring, a cam plate mounted for turning on said stud outwardly of said spring and having a cam lobe on the face thereof adjacent to said spring for moving into and out of engagement with the intermediate portion of said spring as said cam plate is turned for flexing and relaxing said spring as said cam plate is turned, and a handle extending laterally from said cam plate to provide for manually'turning the same.

References Cited in the file of this patent UNITED STATES PATENTS 465,557 Diehl Dec. 22, 1891 885,824 Zanzig Apr. 28, 1908 1,197,265 Cor'son Sept. 5, 1916 1,217,540 Wappat Feb. 27, 1917 FOREIGN PATENTS 491,040 Germany Feb. 8, 1930 606,904 Germany Dec. 13, 1934 641,450 Germany Feb. 2, 1937 76,578 Holland Dec. 15, 1954 

